234 BULLETIN 195, UNITED STATES NATIONAL MUSEUM 



nesting cavity inside. Entrance is effected through a five-inch tunnel. The 

 lining is almost always profuse and is usually of the feathers of some larger 

 bird. Sometimes it is of plant down and in one nest nothing was used but native 

 cotton. 



There are three nests and nine eggs of this wren in the Thayer col- 

 lection in Cambridge, all collected in the Cape region, on May 1, Au- 

 gust 3, and August 18. The nests are substantially built as described 

 above, but one is made externally of dry grasses, dry leaves, fine twigs, 

 rootlets, and lichens; it is lined with very fine grasses. The second 

 one is similar. The third is made chiefly of dry grass stems, mixed 

 with a lot of poultry feathers and a few pieces of rags, string, and 

 cotton ; it is profusely lined with feathers and white hairs ; the feathers 

 stick out all over it; evidently the wrens had secured most of their 

 material from some farmyard. 



Eggs. — Evidently the San Lucas cactus wren seldom lays more 

 than 3 eggs, and often fewer. The three sets referred to above consist of 

 3 eggs each. Mr. Bancroft (1930) states that "the number of eggs 

 laid is 2. Of the many sets examined I found but one that contained 

 3 eggs. Incubated singles were unusual rather than rare. The laying 

 season begins about April 25, in a desultory way, and is not under 

 full head until past the middle of May." J. Stuart Rowley (1935) 

 says that "of some 35 nests examined, none contained more than 3 

 eggs or young, with the majority holding two." 



The eggs probably show all the variations to be seen in the eggs of 

 other races of the species. The 9 eggs referred to above vary from 

 ovate to ellii^tical-ovate and are somewhat glossy ; they are mostly of 

 the lighter types of coloration. The measurements of 40 eggs in the 

 United States National Museum average 23.7 by 17.0 millimeters; the 

 eggs showing the four extremes measure 25.9 by 17.8, 19.8 by 18.3, and 

 23.4 by 15.8 millimeters. 



Plumages. — Mr. Brewster (1902) writes: 



Young in juvenal plumage differ from old birds in breeding plumage only in 

 having the crown of a darker, duller brown (almost slaty brown In some speci- 

 mens) ; the light markings of the back rusty white and broader, on many of the 

 feathers taking the form of deltoid spots; the light markings of the wings, in- 

 cluding those of the outer primaries (but not the tail), strongly rusty; the 

 spotting of the under parts finer and somewhat fainter. 



Young (and perhaps old birds also) in autumn differ from spring adults and 

 young in juvenal plumage in having the light streaks of the back broader and 

 whiter ; the flanks, abdomen, anal region, and crissum bright cinnamon or 

 ochraceous buff, instead of rusty white. 



HELEODYTES BRUNNEICAPILLUS PURUS van Rossem 

 SAN IGNACIO CACTUS WREN 



In describing this subspecies, Mr. van Rossem (1930) says that it 

 "differs from all of the known races of Heleodytes hrunneica'piUus in 

 possessing, when in relatively unworn plumage, pure black and white 



